Rayon Flame-Retardant Fabric With Phosphorus-Rich Outer Filaments
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Solution Overview
Problem
Existing flame retardant fabrics made from Nomex fibers are uncomfortable in hot environments and limited in color options, while fabrics made from continuous filament rayon lack effective flame retardant properties when treated with conventional phosphorus-based compounds.
Innovation Solution
A textile fabric formed from yarns of continuous filament rayon, treated with a modified phosphorus-based flame retardant process where the outer filaments have a phosphorus content at least 25% greater than the inner filaments, using a dip-squeeze technique with hydroxymethyl phosphonium compounds, resulting in improved flame retardancy and comfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional phosphorus-based flame retardant treatment is applied to continuous filament rayon fabric, then flame retardant properties are provided, but inadequate flame retardant performance is achieved
Solution Approach 1:
The patent applies local quality by creating a non-uniform distribution of phosphorus content within the yarn structure. Specifically, the outer filaments of the yarn are treated to have higher phosphorus content (at least 25% greater) compared to the inner filaments. This localized concentration of flame retardant compound at the yarn periphery provides effective flame protection while maintaining the overall fabric properties.
2Reliability
If Nomex fiber is used for flame retardant properties, then inherent flame retardancy is achieved, but comfort and moisture-wicking properties deteriorate
Solution Approach 1:
The patent changes the chemical composition parameters of the rayon fiber by incorporating phosphorus-based flame retardant compounds. This modifies the fiber's properties to achieve flame retardancy while maintaining the hydrophilic nature of rayon. The specific parameter change is the phosphorus content distribution, with outer filaments containing at least 25% greater phosphorus than inner filaments, enabling the material to resist flame while preserving comfort characteristics.
3Ease of operation
If continuous filament rayon is used for comfort and moisture-wicking, then skin contact comfort is improved, but flame retardant properties are lost
Solution Approach 1:
The patent creates a composite structure within the yarn by combining treated and untreated filament portions. The outer filaments are impregnated with phosphorus-based flame retardant compounds while the inner filaments retain their original rayon properties. This composite approach allows the fabric to exhibit both flame retardant behavior (from the phosphorus-treated outer layer) and comfort/moisture-wicking properties (from the untreated inner core).
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The treated fabric exhibits enhanced flame retardant properties, increased stiffness, and maintains moisture-wicking and comfort characteristics, suitable for close-fitting garments and various applications, including firefighting and high-visibility safety apparel.
Implementation Method 1
a cured phosphorus-based flame retardant compound durably affixed to the filaments and imparting flame retardant properties to the fabric
Implementation Method 2
curing the compound on the fabric
Data Source
AI summary
A high performance flame retardant textile fabric is provided which is suitable for use in producing close-fitting garments, such as undergarments, that come into direct contact with the skin of the wearer and provide a protective function, as well as in non-apparel applications. The fabric is formed of yarns of rayon continuous filaments, the yarns having outer filaments along the periphery of the yarn and inner filaments in the interior of the yarn. A cured phosphorus-based flame retardant compound is durably affixed to the filaments and imparts flame retardant properties to the fabric. The outer filaments of the yarns have a phosphorus content at least 25% greater than the inner filaments of the yarn.